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arXiv · 2001.04717

Increasing two-photon entangled dimensions by shaping input beam profiles

Shilong Liu·Yingwen Zhang·Chen Yang·Shikai Liu·Zheng Ge·Yinhai Li·Yan Li·Zhiyuan Zhou·Guangcan Guo·Baosen Shi
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Abstract

Photon pair entangled in high dimensional orbital angular momentum (OAM) degree of freedom (DOF) has been widely regarded as a possible source in improving the capacity of quantum information processing. The need for the generation of a high dimensional maximally entangled state in the OAM DOF is therefore much desired. In this work, we demonstrate a simple method to generate a broader and flatter OAM spectrum, i.e. a larger spiral bandwidth (SB), of entangled photon pairs generated through spontaneous parametric down-conversion by modifying the pump beam profile. By investigating both experimentally and theoretically, we have found that an exponential pump profile that is roughly the inverse of the mode profiles of the single-mode fibers used for OAM detection will provide a much larger SB when compared to a Gaussian shaped pump.

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Shilong Liu, Yingwen Zhang, Chen Yang, Shikai Liu, Zheng Ge, Yinhai Li, Yan Li, Zhiyuan Zhou, Guangcan Guo, Baosen Shi. 2020-01-14. Increasing two-photon entangled dimensions by shaping input beam profiles. https://doi.org/10.1103/physreva.101.052324

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